Electrical installations temporary

In this chapter we have looked at many different types of electrical installations and wiring systems. Most of this type of work is carried out alongside other trades as a part of the construction process. Electricians have an important part to play in any construction project. However, a construction site has the potential to be hazardous because of the temporary and changing nature of the building environment. We have looked at the common causes of accidents at work and how to control the risks associated with various hazards in earlier chapters of this book. To make your work environment safe always ... 

The principal contractor normally provides the temporary electrical installation. If he has an in house electrical department, he may well install and maintain the installation and, in such a case, he is responsible for its safety. The electrical staff member in charge of the site installation will exercise the technical responsibility. This official should ensure that the planned maintenance is done and that defects and breakdowns are reported and rectified immediately. Some main contractors hire the distribution equipment and arrange for the hirer to install and maintain it. As the occupier, they still retain responsibility for the safe use of the electrical installation, but responsibility for its maintenance in a safe condition rests on the hirer who should appoint competent, electrically qualified persons to do the work. 

Construction sites are a special case. The electrical installation is temporary and is altered from time to time to meet the changing needs of the con-... 

Electrical installations, whether temporary or permanent, together with electrical equipment and apparatus, should be protected by a range of measures including residual current devices (RCDs) which protect human beings from electrical shock, fuses and miniature moulded case circuit breakers (MCCBs) which provide protection to apparatus from overheating and short circuits. Arrangements should be in place to ensure that all electrical work to installations and/or electrical equipment is undertaken by only trained, qualified and competent electricians who are familiar with the systems involved. 

Temporary electrical supplies on construction sites can save many person-hours of labour by providing energy for fixed and portable tools and lighting. However, as stated previously in this chapter, construction sites are dangerous places and the temporary electrical supplies must be safe. lET Regulation 110.1 tells us that all the regulations apply to temporary electrical installations such as construction sites. The frequency of inspection of construction sites is increased... 

Provide adequate illumination for work activities. Equip temporary lights with guards to prevent accidental contact Install all wiring and electrical equipment in accordance with the National Electric Code... 

The source of supply for the temporary installation may be from a pietrol- or diesel-generating set or from the local supply company. When the local electricity company provides the supply, the Incoming cable must be terminated in a non-combustible or not readily combustible waterproof and locked enclosure to prevent unauthorized access and provide metering arrangements. 

Subpart K deals with the means of providing electrical power, both permanent and temporary, to a jobsite. Subpart K also states that the electrical standards do not apply to existing permanent installations that were on the site before construction began. There are four major divisions of this subpart including installation safety requirements, safety-related work practices, maintenance and environmental considerations, and requirements for speciai equipment. 

All portable electrical tools and equipment must be grounded or of double insulated type. Electrical appliances such as vacuum cleaners, polishers, and vending machines must be grounded. Extension cords being used must have a grounding conductor. Multiple plug adapters are prohibited. Ground-fault circuit interrupters should be installed on each temporary 15- or 20-ampere, 120-volt AC circuit at locations where construction, demolition, modifications, alterations, or excavations are... 

---